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Safety within nuclear power plants: Manmade radiation risks, hazards

Jul 17,2021 - Last updated at Jul 17,2021

Peaceful nuclear applications do not tolerate any frivolous treatment. This is important, due to the fact that the forces within the nucleus of an atom are large enough to respond to any irresponsible behavior. At no point can you weaken your vigilance and depend on chances, hence you have to be ready for anything that may happen. Domestication of the atom, commonly refers to the first period of the development of nuclear power, as if it is a predator, such a comparison is perfectly fair to a monster who could at any moment throw itself at its inexperienced coach.

Important questions which are often directed to the creators of the nuclear energy sector: Are you, at the present time, "skilled trainers"? Did you take into consideration the mistakes made by the predecessor on his difficult path? What will guarantee that we will not fall into the same atomic crater again, and that we will not have to deal with disasters such as the Three Mile Island, Chernobyl and Fukushima? Therefore, in order to assert its right of survival and development, the Global Nuclear industry must reduce the probability of radiological accidents in nuclear power units under construction to the lowest acceptable level.

As a start, it is logical to look at things in a concentrate way. What information do we know about radiation? Radiation is quite dangerous, and that is a fact, however Solar Radiation is also dangerous, in case of exposure to high doses of it. Furthermore, a radiation accident can lead to serious consequences, and this is also a fact. However, it is fair to say that man-made radiation is not the only dangerous factor that has a role in its formation. Of course, radiation accidents have certain characteristics and features, but at the same time it represents a much broader segments of other man-made accidents.

It should also be noted that "man-made accident" is rather a vague term. It can be illustrated in simpler form as a link to a defect in equipment and devices. As it is well known, the nuclear power unit, mainly the reactor, consists of many artificial devices.

Humanity had faced different kinds of man-made dangers, long before the phenomenon of radioactivity was discovered. Back then, people had created special technologies in order to facilitate life and work, such as equipment used in construction, agriculture, factories and so on. Human-caused accidents are not a new phenomenon, for example, mine collapses due to the use of poor and invalid beam girders are primarily caused by the flagrant violation of safety requirements.

There are many possible causes for an accident, such as: Design errors, violation of operation rules, negligence of personnel, usage of worn equipment, natural disasters, manufacturing defects and the list goes on.

The Chernobyl tragedy can be ignored, in fact, the explosion which occurred in April 1986 in the fourth unit of the Chernobyl nuclear power plant, for many is considered as snow on the heads, meaning that it was not that serious, but it must be admitted that the event that occurred was not the first accident caused by “out-of-control” nuclear energy, that accident turned out to be one of many less important accidents which had happened before.

The first serious accident of a power reactor, which attracted the attention of the entire world community, occurred back in 1979, at the US nuclear power plant, in Three Mile Island. The primary cause of the accident was technical malfunctions in the filters designed to clean the turbine condenser. Subsequent errors made by plant personnel, along with an emergency system failure, disrupted the cooling system, which led to a partial meltdown in the reactor core, causing an accident in a nuclear boiler. Some of the radioactive isotopes did penetrate the protection systems of the power unit and spread into the surrounding environment. Fortunately, the number of emissions was very small, and the doses received by the residents as a result of this accident were extremely small.

As for other nuclear countries, have any conclusions have been reached regarding this incident? Certainly. To start with, the importance and degree of dependence on people appeared: Had it not been for the wrong actions of individuals, also the meltdown that occurred in the reactor core could have been avoided. Also, continuous monitoring of the integrity of safety systems has become inevitable. And, nuclear scientists recognised the need to further strengthen safety systems: That if any of their elements failed, the rest had to deal with the consequences and prevent any accident of any kind and degree of severity, because any simple accident would generate a chain of more serious accidents.

In Chazma Bay in 1985, a huge mistake was made while reloading nuclear fuel in the Soviet atomic submarine K-431, which led to a powerful explosion that is considered to be the most dangerous of all. The amount of energy emitted was so great that the transmission equipment burned and evaporated, the floating crane ruptured and fell into the bay, and the reactor cover, weighing 12 tonnes, flew vertically at a height of several hundred meters and then fell on the submarine, destroying it.

As a result, ten sailors who were reloading fuel died instantly, and their bodies simply disappeared due to the force of the explosion. All in all, 290 people were injured, and most of them were military personnel. The radiation emission caused great pollution to the bottom of Chazma Bay, and the village near the incident area was affected.

In the eighties of the 20th century, the nuclear industry had established itself as one of the most successful areas of the Soviet industry. It is easy to express the general mood that prevailed at the time with the phrase "nothing wrong can happen." But this euphoria, though justified, but remained partial. Did the developers of the RBMK-1000 reactor know its weaknesses? Unfortunately, yes. They were aware of this. At the Lenin Institute of Energy Engineering, the Scientific Research NIKIET, and at the Kurchatov Institute of Nuclear Energy, important reports were presented about the deficiencies identified during the operation of the reactor.

However, sole "paper-based" procedures were not enough, and there was an urgent need to develop new and more advanced security systems. An important vital pivot was the creation of mechanisms to prevent wrong actions by individuals.  Unfortunately, none of this was implemented. Prior to the 1986 accident, none of the proposed protocols to improve the performance of the RBMK reactor had been implemented in any of the nuclear power plants. It seems that the management considered that just having highly qualified professionals sitting behind the control panel would be enough and would prevent a major disaster to happen.

Although many institutes were established to train engineers in the nuclear industry, but at the same time the administration began to attract employees "from abroad", i.e., from related industries, to work in Nuclear Power plants. As a result, specialists in thermal engineering and hydroelectricity began to go to nuclear power plants, people who are not familiar with Nuclear Physics. They viewed the nuclear reactor as a "kettle" but with a different fuel. Needless to say, it is a bad sign when the operator behind the control panel treats the reactor as a boiler.

The safe culture at Soviet nuclear facilities in the 1980’s was not at its best; this is the least to be said, but the accident in Chazma Bay just nine months before Chernobyl served as an early alert for decision makers to seriously think about how important are the human factor is, same as the qualifications, and the level of specialists who perform operations in the nuclear reactor.

The veil of secrecy that extended to nuclear energy was a big flaw, as information about radiation accidents were classified, and no one was allowed to overview them, for example: many nuclear scientists learned about the melting of a part of the reactor core at the Leningrad nuclear plant in 1975 after the Chernobyl reactor accident. This happened, in the nuclear plant in which specialists were not afraid to commit mistakes, simply because they had no idea what the consequences of their wrong actions might be.

As it is well known, the Chernobyl reactor disaster occurred during the conduction of experiments, where the task set by the station staff was to find out how long the shaft of the turbine generator could rotate by inertia after turning off the steam supplies. “Off-time”, as experts call it, is an important factor from a safety perspective. Thus, in the end, a paradox arose, the worst accident in the history of nuclear energy occurred as a result of measures intended to improve safety.

Major accidents in nuclear power plant units, not to mention a series of minor accidents, made it clear that humor about Nuclear Power is out of question, and in order to avoid similar events in the future, the "wild beast" needs an effective and reliable "bridle". There are two main things that need to be done. The first, purely technical, involves the introduction of reliable protection systems. The second trend is related to humans, and it is to maintain a high level of safety culture among individuals.

In general, “cultural-safety” is a not new concept, as it was first expressed in the report devoted to the analysis of the Chernobyl accident in 1986. Later, this term was included in official regulatory documents. The culture of safety is directed directly to the human beings, as it includes a high level of training of specialists working in nuclear power plants.

It seems that things are now getting clearer, the Chernobyl accident has shown how dangerous it is to allow someone without specialised knowledge to work in a dangerous, and radioactive facility. This is especially true for operators in control rooms, who have the responsibility to directly control the nuclear power unit. These people must be very professional, familiar with all the details, and rationales that occur in the uranium "kettle" and related systems.

Despite its importance, good professional knowledge is not the only part of the safety culture, where the psychological behaviour of the specialist plays an equally important role, this behavior begins from universities, technical colleges, and continues, in fact, until the specialist reaches the nuclear plant, it is important to ensure that safety measures become a major goal and a self-motivated desire within the nuclear engineer.

This task is not simple as it may seem, it is necessary that the competent person be "saturated", that is, it is necessary to feel, on the internal level, responsibility for the result of any action that may affect the safety of the nuclear unit. If the employee realises the potential consequences of any mistake, he or she may do, this will result in becoming the best observer, and judge for their actions, which in turn can greatly reduce the possibility of errors due to negligence.

To achieve a high safety culture, it is not enough to educate the employee, but it is necessary to form a methodology that prevents the specialist from taking any risky action, even if the possibility of unwanted risks arises from it is low. The goal is achieved by creating an atmosphere of openness, which promotes an intense exchange of experiences, as well as an essential point of "debriefing", through the analysis of mistakes made under certain circumstances which in turn leads to an accident. This allows to rule out the peace of mind, where a specialist might convince himself of his wrong decisions, by reassuring himself that nothing serious happened.

Nuclear safety is the product of experience that mankind gained over time, to form a set of regulations rules agreed upon in the present. In order for objectives to be achieved and translated into reality, where everyone must follow without exception. It can truly be said that the culture of safety for the global nuclear industry as a whole is a matter of survival.

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